From the age of 2 weeks, male KO mice and their littermate fGluN1 control mice received apocynin (APO, 1-(4-Hydroxy-3-methoxyphenyl) ethanone, Sigma-Aldrich, St. Louis, MO) in drinking water (7.5μg/ml) until behavioral evaluation (Figure 2A). Given that mice with body weight of 20 g drink 13 ml of water per day (13), APO was orally administered at 5 mg/kg per day. Since studies showed no detectable decay of apocynin at room temperature in 7 days (17), freshly prepared APO water bottles were replaced weekly. Apocynin is an antioxidant and scavenger of ROS (18) although it may act as an NADPH oxidase inhibitor in the presence of myeloperoxidase activity (19). Group-housed or PWSI animals underwent the following behavioral tests, the protocol of which were previously described (15; see Supplement 1): 1) the elevated plus maze and open field tasks at 8 weeks of age; 2) the spontaneous alternation Y-maze test and pre-pulse inhibition at 8 and 12 weeks of age; 3) acoustic startle reflex at 12 weeks of age; 4) the saccharine preference test at 14 weeks of age; 5) the nest building behavioral test at 8, 12, and 16 weeks of age.
